Side Exiting Wheelchair
A wheel assembly for a wheel chair allows the occupant to transfer laterally without encountering obstruction from a fixed mobilization or transfer wheel. In one embodiment the wheel is slid rearward and locked to allow the occupant to transfer laterally in front of the slidable wheel. In another embodiment a chordal portion of the wheel is temporarily removed to allow transfer over the remaining portion of the wheel. Another embodiment enables the chair occupant to mobilize vertically to allow lateral transfer over a standard fixed mobilization wheel; alternately, a further embodiment allows the occupant to mobilize forward to allow lateral transfer in front of a standard fixed mobilization wheel.
This patent application makes reference to and thereby hereby incorporates all information found in the provisional patent application numbered Ser. No. 61/964,284 entitled Side Exiting Wheelchair, filed 30 Dec. 2013 by William J. Drasler, et. al., and found in provisional patent application numbered Ser. No. 61/955,827 entitled Side Exiting Wheelchair Device filed 21 Apr. 2014 by William J. Drasler, et. al.
FIELD OF THE INVENTIONThis invention relates to a wheelchair device that incorporates a novel means to eliminate the side barrier, such as a wheel obstruction, for example, so that the occupant can transfer into or out of the chair without having to transfer around or over the wheel. A number of embodiments are described for a wheelchair system that enables the occupant to remove the side barriers without assistance.
BACKGROUND OF THE INVENTIONOne of the common difficulties for wheelchair—bound individuals is the challenge they face when transferring to a fixed chair, toilet, car seat, or other platform. The only way they can perform the transfer is to stand up and exit the chair out the front, then pivot and sit down, hoping that they are on target.
Many aids have been developed to assist in the transfer process, but they are usually cumbersome, expensive, take too much time to employ, or require the assistance of a caregiver. Most wheelchair-bound occupants have enough strength to push themselves out of the chair, but not enough balance or leg strength to confidently execute the transfer without assistance. The resulting frustration at not being able to perform this frequent transfer maneuver diminishes the quality of life and increases the feeling of dependence of the wheelchair-bound individual.
If a reliable method for independent transfer can be developed, it would realize many significant benefits. From a safety perspective, the method would minimize the risk of falls and the long-term ramifications from unnecessary injuries. Additionally, cost-savings may be realized by reducing need for medical assistance and personal attendants. Being able to transfer oneself in an independent manner promotes confidence and raises self-esteem; it also assists in maintaining upper-body strength.
SUMMARYThe present invention offers novel solutions for side-transfer of a wheelchair-bound individual that do not require assistance. Several embodiments of the invention are described which can be used to modify an existing wheelchair, used with an existing wheelchair, or can be included in the initial design of an improved wheelchair design. One of the embodiments comprises an occupant-actuated lift mechanism that removes the weight from the transfer or mobilization wheel so that the wheel can be rotated into the correct position or slid out of the way. This embodiment can be used with other embodiments of the invention in order to provide the other embodiments a greater level of utility via the operator. Other embodiments allow the occupant to transfer over a portion of the wheel or allow the wheel to be moved rearward so that the occupant can transfer in front of the wheel.
The method of operation allows the occupant to independently side-transfer from the wheelchair onto another platform or target location. The occupant accomplishes this task by removing the chair obstacles to side-transfer, such as its wheel, for example, and physically sliding their body across the now-clear pathway into the desired target location.
In one embodiment the method is described via the following steps. The occupant rolls the chair into the appropriate orientation in proximity to the target platform location. The occupant then activates the lift mechanism to stabilize the chair and raise the wheel located on the side of the chair intended for transfer slightly off the ground. The occupant removes the barrier presented by the wheel by rotating the wheel such that the separable chordal segment is rotated to the top of the rotation and removing or folding the chordal segment. The occupant may lower the wheel by raising the lift mechanism, or may leave the wheel in a freewheeling state during transfer of the occupant. The occupant slides himself or herself across the chair and onto the target platform.
In another embodiment the occupant wheels into position and raises the wheel on one side as described in the previous embodiment. The occupant is then able to slide the wheel rearward to allow the occupant to transfer to the target location in front of the wheel.
In one embodiment of the present invention both of the wheels have a removable chordal segment of such a dimension as to remove the obstruction that the wheel would present during side-transfer. In this embodiment the wheel segment is removed by the occupant and set aside. The structure of this embodiment is such that, when assembled, the chordal segment matches up to the non-chordal segment to ensure that the resulting wheel perimeter is round and smooth. A pair of alignment pins is used to establish the connection between the chordal and non-chordal segments. The pins may be located in either segment, or may have one pin in one segment and the second pin in the other segment, and will match up with a pair of holes (one hole may be elongate to facilitate ease of assembly or removal) in the opposite segment. The pins have a locking mechanism that locks the two segments together when activated by the occupant. In this embodiment, a lift mechanism can be incorporated as an integral part of the wheel that, when activated, raises the wheel slightly off the ground to permit the occupant to rotate the wheel such that the chordal segment is at the top of the rotation. The lift mechanism may consist of a toggle mechanism that is operated manually by means of a lever by the occupant. The toggle mechanism frame is incorporated as a concentric member of the wheel such that it does not add to the overall width of the wheelchair, and is mechanically anchored to the stock frame to provide stability and to prevent the lift mechanism from inadvertently rotating during operation. The lift may, or may not, be deactivated once the wheel has been rotated to the top at the preference of the occupant. A variant of the first embodiment, the wheel chordal segment pivots out of the way by means of a hinged joint but remains attached to the main body of the wheel. The occupant releases a locking mechanism and folds the segment over out of the plane of the wheel. Alternatively, the hinge (60) may be located at one end of the chordal segment with the hinge pin oriented perpendicular to the plane of the wheel, allowing the occupant to pivot the segment in the plane of the wheel such that the segment ends up behind the non-chordal segment.
In yet another embodiment, the wheel can be comprised of more than one chordal segment each of which can be attached to the main non-chordal segment of the wheel. For example, three chordal segments can be attached to generally triangular-shaped wheel to form a circular wheel. Removal of any one of the chordal segments provides the wheelchair occupant with an improved positioning of the appropriate chordal segment that would allow the occupant to transfer laterally from the wheelchair.
An alternate embodiment of the present invention has a solid wheel connected to a sliding mechanism that permits the occupant to slide the wheel back and out of the way. The sliding mechanism consists of two main elements, a fixed member that consists of a linear bearing surface and a mounting means to attach the fixed base to the wheelchair frame, and a sliding member. The sliding member consists of a linear bearing surface, low-friction sliding means (either rolling elements or low-friction material), a lock mechanism for preventing the slide from functioning at either end, or at any intermediate position, of the sliding member, and a means to attach the axle of the wheel to the sliding member. An integral lift mechanism can be built into the fixed member; the lift mechanism can be powered or operated by the occupant.
The fixed member is constructed in such a manner as to permit it to be attached to most stock wheelchair frames without requiring modification of the stock frame. One means to attach the fixed member to a stock frame would be to use strategically placed bolt holes along the length of the fixed member such that a U-bolt may be passed around the tubular members of the stock frame and through the appropriate hole pattern in the fixed member. The fixed member also is the base to which the lift mechanism and the linear bearing are attached. The linear bearing is the carrier of the rolling or sliding elements and the sliding member.
The lift mechanism may be either powered or manually operated by the occupant. If powered, the lift mechanism may consist of a coarse-thread jackscrew driven by a nut that is rotationally connected to a motor drive. Alternatively, the motor may drive a linkage that moves a lift leg up and down to accomplish the task of raising the wheel. If the lift mechanism is manually operated by the occupant, it is powered by the occupant raising or lowering a lever to operate a toggle linkage to raise and lower the lift leg. The toggle mechanism is designed to only require a force easily generated by an average wheelchair bound individual to accomplish the raising of the wheel off the ground.
The sliding member permits the occupant to move the wheel forward or back in order to position it in the desired location, either for normal use or for transfer. The sliding member also contains a lock mechanism, which enables the occupant to lock or unlock the wheel in any position relative to the wheelchair frame along the slidable length of the linear bearing. The sliding member includes a structure that connects the stock wheel to the sliding member by means of an axle. The axle may be the original axle or it may need to be a modified custom axle that is designed to mate to the sliding member.
In one embodiment of the sliding wheel, a locking means is placed onto the front wheel of the wheel chair on the side that the occupant wishes to transfer. Rotation of the large mobilization or transfer wheel in a rearward direction is used to allow the wheel to slide rearward and provide access for the occupant for transfer.
In still another embodiment of the invention a sliding seat is placed on top of the chair sitting base that would allow the wheelchair occupant to easily slide forward in the wheelchair to a position that would allow lateral transfer of the occupant in front of the transfer wheel. The chair base can be a planar member or soft foldable member that is placed onto the wheelchair frame after the wheelchair has been unfolded into its normal wheelchair width; the chair base forms a solid base onto which a sitting pad or cushion can be placed to provide a sitting surface for the occupant. An alternate movable caster wheel can be positioned at the front of the wheelchair to ensure that the wheelchair is stable against a forward rotation of the wheelchair during lateral transfer.
In still yet another embodiment of the invention a raised seat assembly is placed on top of the wheelchair sitting base that would allow the wheelchair occupant to become elevated to a location above the transfer wheel of the wheelchair to allow lateral transfer without obstacle from the transfer wheel. The raised seat assembly can be activated by an air bladder that is inflated during transfer. Alternately a mechanical lifting mechanism can be used to provide the elevation of the raised seat.
It is understood that any of the embodiments of the present invention can be combined with other embodiments to form a system to provide lateral transfer from a wheelchair. For example, the present invention could include a rearward sliding wheel with a forward sliding seat (or raising seat) such that each aspect of the invention contributes a portion of the benefit that provides for lateral transfer for the wheelchair occupant.
The present invention is a wheel assembly that can be affixed to an existing wheelchair (20), the design of which permits the main mobilization wheel to either be rotated into alignment and a portion of the wheel to be removed, the wheel slid back out of the way, or the seat of the wheelchair slid forward or upward such that the wheel is not an obstacle for the occupant to side transfer out of the chair. The invention is understood to apply to both mobilization wheels of a conventional manpowered wheelchair.
In one embodiment of the present invention, shown in
The chordal segment (10) is connected to the non-chordal segment (15) by any number of mechanical attachment methods, all of which would be designed for ease of removal, alignment, and reattachment by the occupant. Alignment and retention pins (30), sliding interlocking surfaces (35), and cam locks (40) are just a few of the means by which the two wheel segments could be fastened together.
As shown in
Another embodiment of the wheel assembly (72), shown in
The fixed member (95) consists of a plate that can be connected to the wheelchair frame (45) without requiring the frame (45) to be modified, and a bearing surface on which the slidable member (80) is moved back and forth relative to the fixed member (95) by the occupant.
The embodiment for the wheel assembly (72) shown in
In the embodiments shown in
One embodiment of the lift mechanism (100) is a motorized mechanism shown in
An alternate embodiment of the lift mechanism (100) shown in
The fixed platform (140) of the sliding seat assembly (130) can be formed from a polymeric, wood, or metal material to provide the strength required to support the sliding seat (145), which can be formed from similar materials. The fixed platform (140) can also be used to provide the function of the chair base (135) if desired, thereby eliminating the need for a separate chair base (135). The fixed platform (140) can be fitted with appropriate fixtures to allow it to attach, or fit, or be placed directly onto the frame (45) of the wheelchair (20).
To provide additional stability against possible forward rotation of the chair during transfer, the wheel caster (165) located at the front of the wheelchair (20) is positioned such that it extends forward with the greatest extent. The wheel caster (165) can be constructed with a larger pivoting arm (170) if necessary to provide additional stability in the forward direction. The wheel caster (165) can be directed to a forward position using a caster lever (175) that is conveniently located for access from the wheelchair occupant.
Another embodiment of the present invention is shown in
Upon inflation of the bladder (190) the raised seat (185) will change its height relative to the ground by approximately 3-6 inches (range 2-8 inches) to raise the wheelchair occupant such that the transfer wheel (5) is no longer providing an obstacle to lateral transfer as shown in
The fixed platform (140) of the raised seat assembly (180) can also serve as the chair base (135) and can be positioned directly upon the wheelchair frame (45) thereby obviating the need for an additional chair base (135). The bladder (190) for the raised seat assembly (180) can be formed from a polymeric material such that those used in the formation of seat cushions for wheelchairs, air mattresses, air inflated bed mattresses, inflatable devices, and the like. The bladder (190) can be supported with fibers if desired to hold the shape and provide for improved stability for the bladder (190) in an inflated condition. The bladder (190) can be formed from a variety of plastics or rubbers that will hold pressures similar to that of an adult; such materials used in air mattresses would be appropriate, for example. The fixed platform (140) and raised seat (185) can be formed from a polymeric, wood, or metal material that is able to provide the support typically provided by a chair base (135) material that is placed or fit onto the chair frame and removed during folding of the chair.
Inflation of the bladder (190) can be accomplished by a disposable carbon dioxide compressed gas cartridge, a compressed gas cylinder, an electrically or battery operated air pump, mechanical pump, or another air supply (200). In one embodiment small compressed air tank (200) is attached to the raised seat (185) assembly (180) or to the frame (45) of the wheelchair (20). An air tube (205) connects the bladder (190) with the compressed air cylinder (200). The compressed air cylinder (200) has a volume of approximately 5-200 cubic inches and stores compressed air at a pressure of approximately 1-10 atmospheres. The compressed air is able to inflate the bladder (190) volume of approximately 1000-4000 cubic inches at a pressure ranging from 0.2-5 psi (controlled via a pressure regulator) to raise the wheelchair occupant with the raised seat (185). The compressed gas cylinder would contain enough compressed gas to raise the raised seat (185) several times before it would require recharging via an electrical pump that could be located at a convenient location within the home or location of choice for the wheelchair occupant. A controller (210) located at the armrest of the wheelchair (20), wheelchair frame (45), or a RF controlled remote control is used by the wheelchair occupant to control the inflation of the bladder (190) via a valve (215) (see
The present raised seat assembly (180) embodiment can be used with other embodiments of the present invention; for example, if the seat were raised a few inches, the amount of required rearward travel of the sliding wheel would be less to accomplish a lateral transfer. Similarly, if the raised seat (185) were raised a few inches (2-4 inches, for example), then a forward sliding seat (145) would only have to slide forward by a few inches (approximately 2-4 inches, for example). Further, if the forward sliding seat (145) moved forward only a few inches (approximately 2-4 inches, for example), the rearward sliding wheel would only have to slide approximately 2-4 inches, for example, to allow for a lateral transfer without obstacle from the transfer wheel. It is understood that each of the embodiments of the present invention can be used along with other embodiments that result in one or more other embodiments that provide a wheelchair (20) of the present invention that enables the occupant to transfer laterally.
As described in
Upon activation of the lock lever (85) by the occupant downward to an intermediate angle (250) as shown in
The slide assembly (75) of the present invention can also contain a wheel-lock assembly (88) as shown in
An alternate embodiment for the slide-lock assembly (86) is shown in
Another alternate embodiment for the wheel-lock assembly (88) for a wheelchair (20) of the present invention having a transfer wheel (5) that is able to be moved rearward is shown in
It is understood that the present invention is not limited to the slide-lock assemblies and wheel-lock assemblies shown in this application and that other mechanism have also been anticipated.
Claims
1-19. (canceled)
20. A transfer wheel for a wheel chair comprising;
- A. a non-chordal segment that is adapted to be mounted onto an axle of said wheel chair, said non-chordal segment having a non-chordal surface,
- B. a chordal segment having a chordal surface that is adapted to be attached to said non-chordal surface to form said transfer wheel with a round assembled shape,
- C. said chordal surface being further adapted to be detached from said non-chordal surface to form said transfer wheel with a non-round disassembled shape,
- D. said chordal surface being held into contact with said non-chordal surface by sliding interlocking surfaces to form said round assembled shape,
- E. said sliding interlocking surfaces being adapted to release said chordal surface from said non-chordal surface to provide said transfer wheel with an unobstructed passage for an occupant of said wheel chair over said non-chordal surface for lateral transfer.
21. The transfer wheel of claim 20 wherein said sliding interlocking surfaces comprise protruding elements that extend from said chordal surface and receptacle elements located on said non-chordal surface.
22. The transfer wheel of claim 21 wherein said protruding elements are inclined protruding elements that extend into receptacle elements comprising inclined receptacle elements.
23. The transfer wheel of claim 21 wherein said protruding elements are locator pins that extend into receptacle elements that are locator holes.
24. The transfer wheel of claim 21 wherein said protruding elements comprise a cam latch mechanism and said receptacle elements comprise a cam seat.
25. The transfer wheel of claim 20 wherein said chordal segment comprises a chord angle ranging from 90 to 180 degrees of said transfer wheel.
26. The transfer wheel of claim 20 wherein said chordal segment comprises a chord angle ranging from 110 to 170 degrees of said transfer wheel.
27. The transfer wheel of claim 20 further comprising a wheel lift for raising said transfer wheel off of the ground.
28. A transfer wheel for a wheel chair comprising;
- A. a non-chordal segment that is adapted to be mounted onto an axle of said wheel chair, said non-chordal segment having a non-chordal surface,
- B. a chordal segment having a chordal surface that is adapted to be attached to said non-chordal surface to form said transfer wheel with a round assembled shape,
- C. said chordal surface being further adapted to be detached from said non-chordal surface to form said transfer wheel with a non-round disassembled shape,
- D. said chordal surface being held into contact with said non-chordal surface by sliding interlocking surfaces to form said round assembled shape, said sliding interlocking surfaces comprising protruding elements that extend from said chordal surface and receptacle elements located on said non-chordal surface,
- E. said sliding interlocking surfaces being releasable to release said chordal surface from said non-chordal surface to provide said transfer wheel with an unobstructed passage for an occupant of said wheel chair over said non-chordal surface for lateral transfer.
29. A transfer wheel for a wheel chair comprising;
- A. a non-chordal segment that is adapted to be mounted onto an axle of said wheel chair, said non-chordal segment having a non-chordal surface,
- B. a chordal segment having a chordal surface that is adapted to be attached to said non-chordal surface to form a perimeter for said transfer wheel having a round assembled shape,
- C. said chordal surface being further adapted to be detached from said non-chordal surface to form said transfer wheel with a non-round disassembled shape,
- D. said chordal surface being held into contact with said non-chordal surface by sliding interlocking surfaces to form said round assembled shape, said sliding interlocking surfaces comprising protruding inclined surfaces that extend from said chordal surface and inclined receptacle surfaces located on said non-chordal surface.
Type: Application
Filed: Dec 21, 2014
Publication Date: Jun 23, 2016
Inventors: William Joseph Drasler (Minnetonka, MN), Richard Charles Kravik (Champlin, MN), Mark Lynn Jenson (Greenfield, MN), William Joseph Drasler, II (Minnetonka, MN)
Application Number: 14/578,470